How do I solve this?

Instructions: Enter your responses rounded to two decimal places. If you are entering any negative numbers be sure to include a negative sign (-) in front of those numbers.

U.S. real gross domestic product changed from $11.5 trillion in 1998 to $14.8 trillion in 2008. During that same time period, the share of manufactured goods (e.g., cars, appliances) of U.S. real gross domestic product was 12.4 percent in 1998 and 12.6 percent in 2008. What was the dollar value of manufactured output

a. In 1998? _____ trillion?

b.In 2008? ____ trillion?

c. By how much did the dollar value of manufacturing output change?

It ____________ (increased/decreased) by ______%